*This paper examines whether parental beliefs about the returns to early-life investments align with recent evidence emphasizing the first 1,000 days of life as a critical window for cognitive development and long-run human capital formation. We elicit beliefs from parents in the Philippines using a vignette-based approach that contrasts hypothetical investments made during infancy with those made during the school-age years. To assess the behavioral relevance of these beliefs, we link them to observed parental investments, measured via infant-directed speech captured through naturalistic, child-centered audio recordings (Long-Form Recordings).

**Recent political trends suggest a significant rise in nationalism throughout the world. At the same time, contribution to global public goods shared by several nations (common defense, economic partnerships, environment) is also marked by tensions and unilateral withdrawal. In this paper, I provide an economic theory that links both phenomena and study how variation in foreign attitudes can affect domestic choices in terms of environmental policy. The framework considers a continuum of national agents holding heterogeneous beliefs about the foreign level of pollution reduction effort. Distinct ideological groups are made salient from aggregating views above and below average. Nationalism is then introduced as an identification to the group trusting foreign the least, and makes individuals care about national wealth or conditional cooperators. Voting equilibrium ultimately reflects both self-perceptions and collective influences in the population.